Neocortical long-term potentiation and long-term depression: site of expression investigated by infrared-guided laser stimulation.
AuthorsEder M, Zieglgänsberger W, Dodt HU
JournalJ Neurosci
PubMed ID12196579
'The synaptic site of expression of long-term potentiation (LTP) and long-term depression (LTD) is still a matter of debate. To address the question of presynaptic versus postsynaptic expression of neocortical LTP and LTD in a direct approach, we measured the glutamate sensitivity of apical dendrites of layer 5 pyramidal neurons ... More
Rapid substrate-induced charge movements of the GABA transporter GAT1.
AuthorsBicho A, Grewer C
JournalBiophys J
PubMed ID15849242
'The GABA transporter GAT1 removes the neurotransmitter GABA from the synaptic cleft by coupling of GABA uptake to the co-transport of two sodium ions and one chloride ion. The aim of this work was to investigate the individual reaction steps of GAT1 after a GABA concentration jump. GAT1 was transiently ... More
Inhibition of backpropagating action potentials in mitral cell secondary dendrites.
AuthorsLowe G
JournalJ Neurophysiol
PubMed ID12091533
'The mammalian olfactory bulb is a geometrically organized signal-processing array that utilizes lateral inhibitory circuits to transform spatially patterned inputs. A major part of the lateral circuitry consists of extensively radiating secondary dendrites of mitral cells. These dendrites are bidirectional cables: they convey granule cell inhibitory input to the mitral ... More
Development and application of caged ligands for neurotransmitter receptors in transient kinetic and neuronal circuit mapping studies.
AuthorsHess GP, Grewer C
JournalMethods Enzymol
PubMed ID9661164
Synthesis, photochemistry, and biological characterization of photolabile protecting groups for carboxylic acids and neurotransmitters.
AuthorsGee KR, Carpenter BK, Hess GP
JournalMethods Enzymol
PubMed ID9661143
Caged compounds: photorelease technology for control of cellular chemistry and physiology.
AuthorsEllis-Davies GC
JournalNat Methods
PubMed ID17664946
Caged compounds are light-sensitive probes that functionally encapsulate biomolecules in an inactive form. Irradiation liberates the trapped molecule, permitting targeted perturbation of a biological process. Uncaging technology and fluorescence microscopy are 'optically orthogonal': the former allows control, and the latter, observation of cellular function. Used in conjunction with other technologies ... More
GABA(A) and GABA(B) receptors on neocortical neurons are differentially distributed.
AuthorsEder M, Rammes G, Zieglgänsberger W, Dodt HU
JournalEur J Neurosci
PubMed ID11264682
The distribution of functional neurotransmitter receptors on the surface of neurons is highly relevant for synaptic transmission and signal processing. To map functional GABA(A) and GABA(B) receptors on the somadendritic membrane of rat neocortical layer V pyramidal neurons we used patch-clamp recording in combination with infrared-guided laser stimulation to release ... More
Distribution of functional glutamate and GABA receptors on hippocampal pyramidal cells and interneurons.
AuthorsPettit DL, Augustine GJ
JournalJ Neurophysiol
PubMed ID10899180
The distribution of functional neurotransmitter receptors is an important determinant of neuronal information processing. To map the location of functional glutamate and GABA receptors on individual hippocampal neurons, we photolyzed "caged" glutamate and GABA while measuring the electrical currents resulting from activation of these receptors. Responses to uncaged neurotransmitters were ... More
Mechanism and kinetics of heterosynaptic depression at a cerebellar synapse.
AuthorsDittman JS, Regehr WG
JournalJ Neurosci
PubMed ID9364051
High levels of activity at a synapse can lead to spillover of neurotransmitter from the synaptic cleft. This extrasynaptic neurotransmitter can diffuse to neighboring synapses and modulate transmission via presynaptic receptors. We studied such modulation at the synapse between granule cells and Purkinje cells in rat cerebellar slices. Brief tetanic ... More
On the mechanism of a mutated and abnormally functioning gamma-aminobutyric acid (A) receptor linked to epilepsy.
AuthorsRamakrishnan L, Hess GP
JournalBiochemistry
PubMed ID15182195
A recent report indicates that a lysine-to-methionine mutation (K289M) in the gamma2 subunit of a human gamma-aminobutyric acid neurotransmitter receptor, the GABA(A) receptor, is linked to generalized epilepsy with febrile seizures [Baulac et al. (2001) Nat. Genet. 28, 46-48]. This mutation caused a decreased current response to GABA [Baulac et ... More
How fast does the gamma-aminobutyric acid receptor channel open? Kinetic investigations in the microsecond time region using a laser-pulse photolysis technique.
AuthorsJayaraman V, Thiran S, Hess GP
JournalBiochemistry
PubMed ID10471287
The gamma-aminobuytric acid(A) (GABA(A)) receptor is a membrane-bound protein that mediates signal transmission between neurons through formation of chloride ion channels. GABA is the activating ligand, which upon binding to the receptor triggers channel opening in the microsecond time domain and reversible desensitization of the receptor in the millisecond time ... More
On the mechanism of alleviation by phenobarbital of the malfunction of an epilepsy-linked GABA(A) receptor.
AuthorsKrivoshein AV, Hess GP
JournalBiochemistry
PubMed ID16981722
A mechanism for the alleviation of the malfunction of a mutated (gamma2(K289M)) epilepsy-linked gamma-aminobutyric acid (GABA) neurotransmitter receptor by phenobarbital is presented. Compared to the wild-type receptor, the GABA-induced current is considerably reduced in the mutated (alpha1beta2gamma2(K289M)) epilepsy-linked GABA(A) receptor [Baulac, S., Huberfeld, G., Gurfinkel-An, I., Mitropoulou, G., Beranger, A., ... More
Picrotoxin inhibition mechanism of a gamma-aminobutyric acid A receptor investigated by a laser-pulse photolysis technique.
AuthorsRamakrishnan L, Hess GP
JournalBiochemistry
PubMed ID15938643
The gamma-aminobutyric acid(A) (GABA(A)) receptor, a major inhibitory neurotransmitter receptor, belongs to a family of membrane-bound proteins that regulate signal transmission between approximately 10(12) cells of the nervous system. It plays a major role in many neurological disorders, including epilepsy. It is the target of many pharmacological agents, including the ... More